Lesson -16 -water (post -4)

Good morning boys ! In the last class you learnt about the reasons of depletion of the water table and the causes of ground water depletion.
ANSWER THE FOLLOWING QUESTIONS TO RECALL WHAT YOU LEARNT-
Answer in YES or NO:
1. Increase forest cover will result in lowering of the water table.
2. The water table will be lower in cities than villages.
3.When the ground water is pumped out less than the water that seeps in ,the water table rises up.

LEARNING OUTCOMES OF THIS CLASS-
By the end of this class you will be able to-
-list ways to prevent wastage of water.
-define term drip irrigation
- list and follow ways to minimise wastage of water.
- list the effects of water scarcity on plants

Water covers 71 % of the Earths surface but its distribution is not uniform. Some places are water-rich and some are water deficient.The main factor that is responsible for the distribution of water on the earth is rainfall.
WATER MANAGEMENT
Since useable water is a necessity for all ,it should be managed properly. It can be done in two ways-
1) Preventing wastage of water
- There should not be any leakage in pipes and taps.
-At a personal level, water should be used economically.
- Crops should be irrigated before sunrise or after sunset to prevent loss of water by evaporation.
-Modern methods of irrigation like drip irrigation should be used.


In the method  of drip irrigation ,water is delivered directly at the base of the plant in the form of drops. This is done by laying a network of pipes with side tubings all over the field.
2) Recharging ground water- Recharging of ground water by making the rainwater to percolate into the soil is called rainwater harvesting.

Age old practise of water storage and recharge of groundwater was construction of shallow wells called bawris. They are being revived at many places .




During our daily activities ,a good part of usable water gets wasted.  Little efforts on our part can help to save water.



Can you think of two more ways of saving water in your homes?

EFFECTS OF WATER SCARCITY ON PLANTS

If plants are not watered for a few days they start to wilt ,dry and in a due course die.

Plants need water to-
-get nutrients from the soil.
-prepare food by the process of photosynthesis.
If plants die due to shortage of water , it will lead to-
-loss of green character of our Earth.
-No food from plants.
-No oxygen.
-Not enough rain.
HOTS!
Why is it said that life on Earth cannot exist without plants ?

HOME -WORK

1. Read pages262-263 of the reader.

 EXERCISES TO BE DONE IN YOUR NOTE-BOOK

11.List four ways by which you can save water in your daily activities.
ans: a) Take shorter shower.
b) Turn off the sink faucet while scrubbing utensils .
c) Use a broom and not a hose to clean drive ways.
d) Turn off the tap while soaping hands or brushing teeth.

12. Why do plants need water?
ans: Plants need water to-
-get nutrients from the soil.
-prepare food by the process of photosynthesis.

13. What will happen if plants die due to shortage of water ?
ans: If plants die due to shortage of water , it will lead to-
-loss of green character of our Earth.
-No food from plants.
-No oxygen.
-Not enough rain.

THIS IS ALL FOR TODAY HAVE A GOOD DAY!